#include <cmath>
#include <iostream>
 
int main()
{
    std::cout << "abs(+3.0) = " << std::abs(+3.0) << '\n'
              << "abs(-3.0) = " << std::abs(-3.0) << '\n';

    std::cout << "fabs(+3.0) = " << std::fabs(3.0 - 4.10) << '\n';

    return 0;
} 
